1. Field of the Invention
The present invention relates to the field alignment and securing of large pieces of equipment and structures together and more particularly, but not by way of limitation, to a method and apparatus for aligning and securing auxiliary equipment and structures with respect to a well drilling platform.
2. History of the Prior Art
The present emphasis in locating new sources of hydrocarbon products, namely oil and gas, has given rise to an unprecedented number of rotary drill rigs in operation across the United States and in foreign countries.
However, during this time of greatly increased drilling activity, the cost of drilling equipment and labor has skyrocketed to the extent that efficiency in operation is of paramount importance and can often represent the difference between a feasible drilling operation and staggering monetary losses.
The cost outlay of drill rigs for medium deep wells of twelve thousand feet or the like is so high that operators lease the equipment for very large sums of money on a daily basis. Hence, it is of great importance that the equipment be very portable so that there is a minimum of down time involved in tearing down the equipment, loading it onto a fleet of trucks, moving to a new drill site and setting up a new drilling operation.
However, associated with each drill rig are three major pieces of equipment or structures which must be in accurate alignment with respect to each other. The central structure is the drilling platform, which supports the upright derrick and which is positioned over the borehole site.
Integrally associated with the drilling platform is a rather large structure known in the field as a control room, sometimes referred to as the "dog house". The control room contains an assortment of equipment, including hydraulic and pneumatic pumps, electrical generators, control devices and the like for controlling and operating the drilling function which is taking place on the drilling platform. This necessitates the use of several connecting lines for providing hydraulic fluid, pneumatic lines, electrical cable and fuel lines connecting the control room with the drilling platform. Some of these lines are high-pressure lines and require hard-line connections as opposed to flexible hose connections.
The connecting of the lines between the control room and the drilling platform requires that the control room be very accurately positioned with respect to the drilling platform in order to effect the necessary plumbing and electrical connections.
The third large structure associated with the drill rig is the drilling mud tank that serves to filter and hold the drilling mud for continuous use in the drilling operation. Although the alignment of the mud tank with respect to the drilling platform is not as critical as that of the control room, it is nonetheless important and plays a large factor in set up time to begin a drilling operation.
Prior to the setting up of a drill rig, the site is prepared and leveled to the extent possible depending on the terrain. The drill platform is then placed into position over the prospective bore-hole. The auxiliary equipment, comprising the control room and the mud tank are then placed into position, usually on either side of the platform. The derrick is then pivoted into a vertical position for the drilling operation.
However, since the handling of the auxiliary equipment is usually by large cranes or the like, it is not unusual that as much as three or even four days is spent aligning the control room with respect to the drilling platform in an attempt to make the necessary plumbing connections. This often results in connecting pipes being broken, electrical wiring being damaged and lost time in searching out various shaped adapters in order to complete the connections.
To point out the inefficiency of the present set up procedures, a well of approximately twelve thousand feet only takes about twenty days of drilling time. Therefore, often a fifth of the total time of the drilling operation is spent attempting to align and connect the control room and the mud tank with respect to the well platform.
Another problem associated with the present design of drill rigs is their vulnerability to storms and high winds. The derrick and associated rigging on a medium-size rig will extend some one hundred thirty feet above the top of the platform, which itself is some twelve feet above ground level. Instability comes not only from side loadings due to wind, but occurs during the raising and lowering of the derrick itself and the handling of large pieces of equipment, such as well casing, which must be pulled off of horizontal pipe racks and up to the derrick structure. The side loads and instability caused from wind is often increased due to bundles of drilling tube being carried by the derrick itself in a vertical position. Often during drilling operations in the Plains states, the rig may experience unexpected high winds and gusts resulting in the rig actually being toppled over causing injury or even death to the drilling operators, but at the very least, virtually destroying the drill rig.
The present method of stabilizing the drilling platform consists of one or more large vertically disposed doors hinged along the bottom of the drilling platform. When the platform is in place, the doors are swung outwardly into contact with the ground and secured in an open position in an attempt to effectively increase the surface area of the platform offering extra stability for the platform against side loading.
However, these doors have met with only limited success and every year several drill rigs are destroyed due to toppling over for one reason or another.
Some manufacturers have even resorted to the construction of enlarged drilling platforms to stabilize the rig but this results in wasted space and material and greatly detracts from the portability of the rig.